I. Field of the Invention
The present invention relates to an interface for a digital wireless telephone system. More particularly, the present invention relates to an interface for a digital wireless telephone system that is compatible with standard analog telephones, analog fax machines, and computer modems.
II. Description of the Related Art
Digital wireless telephone systems allow information to be exchanged more efficiently than analog wireless telephone systems. This increased efficiency allows a greater number of telephone calls or other communications to be conducted over digital wireless telephone systems using a given amount of radio frequency (RF) bandwidth. A prominent example of an analog wireless telephone system is the AMPS cellular telephone system employed extensively throughout the United States.
In some instances, the increased efficiency provided by digital wireless telephone systems is so substantial that digital wireless telephone service becomes economically competitive with the traditional analog wire line telephone service. Analog wire line telephone service is the telephone service provided using the conventional wire based telephone system, often referred to as the public switched telephone network (PSTN). Analog wireline telephone systems typically process data in analog format directly, or in a digital representation of the analog data referred to as pulse code modulated (PCM) format. Analog wire line telephone service has traditionally been far less expensive than wireless telephone service.
To provide a complete replacement for traditional analog wire line telephone service, wireless digital telephone systems must be able to accommodate all the services and functions that are currently supported by analog wire line telephone service. These services include fax and computer data transmission.
Although digital wireless telephone systems typically do provide fax and digital data transmission service, the interface to the fax and data service is generally different than that of analog telephone systems. In particular, digital wireless telephone systems process the digital data directly, rather than in the form of tones, as practiced for analog communication systems.
Because of the different interface methods, some analog telecommunication equipment can not be used with the digital wireless telephone systems. In particular, fax machines and computer modems designed for use with an analog telephone system typically cannot be used with a digital wireless telephone system. Therefore, a user converting from analog wire based telephone service to digital wireless telephone service will have to consider the capital investment made in such equipment when determining the cost benefit of switching to digital wireless telephone service.
Therefore, to reduce the cost of transitioning from wire based telephone service to a digital wireless telephone service, it is desirable to provide interface to a digital wireless telephone system that works with analog based wire line telecommunication equipment. In particular, it would be desirable to provide an interface to a digital wireless telephone system that works with standard telephones, fax machines, and computer modems.